Interference-preventer.



T- B. MILLER. INTERFERENCE PREVENTEH. APPLICATION FILED JAN. 6, 1913.

1,127,368. Ptented Feb. 2, 1915.

WITNESSES.

l/VVEIVTOR a? i 7% 72703 5 fl/zZ/ar 6 W I a QzraM/k. Dim/m c/ BY 2 a ATTOR/VEY F SEATTLE'WASHINGTON, ASSIGNOR 0F 0NE HALF I30 THOMAS BURTONMILLER,

nee,

SMITH CANNERY MACHINES COMPANY, OE $EATTLE, WASHINGTON, A CORPORA- TIQNOF WASHINGTON.

INTEBFER-ENCE-PBEVENTEE. I

T all whom it may concern:

Be it known that I, TnoMAs Bnn'ron MILLER, citizen of the United States,residing at Seattle, in the county of King and State of Washington, haveinvented a certain new and useful Improvement inInterference-Preventers, of which the following arts throughout the atelegraph operator;

is a specification.

My invention relates to improvementsin devices known as interferencepreventers that may be connected in circuits with a re ceiving apparatusof a wireless telegraph station whereby radiant Hertzian waves,representing signals, which may emanate from a desired particular one ofdiderent distant wireless telegraph stations that are generating andsending out such waves, may be perceived exclusively and interpreted byand the object of my invention is to provide wireless telegraphstationswith'circuits and apparatus associated there'with whichapparatus shall be adapted to be adjusted to be acted upon by the weakelectric-waves arriving from a far distant station, or by the weak wavesof a nearer station of small power, whereby such waves may be perceivedand interpreted by an operator without interference or interruption bystronger electrical waves which at the same time may be emanating from anearby or from a more powerful distant station. 7

I attain this object by electrical circuits and devices connectedtherewith which are illustrated in the accompanying drawings, wherein--4 Figure 1 is a diagrammatic illustration of circuits and diiferentdevices connected therein which circuits and devices comprise theessential features of my invention, while Fig. 2 illustrates, by a viewin longitudinal vertical section, three electrical helices and by a viewin side elevation it shows a magnetizable core disposed within saidhelices, which helices and core form a part of my invention.

Like reference numerals indicate like drawings;

Referring to Fig. 1 the primary winding of an air core transformer whichis provided with two separate secondary windings 4 and 5.

The lower terminal of the primary winding 3 is indicated as beingconnected with specification of Letters Eatent.

of the drawings 3 is Patented Feb. 2, igifio Application filed January8, 1913; Serial No. 740,385.

- the earth 6 while its upper terminal may extend to connect with theantenna of a wireless telegraph station. The secondary winding 4 has itsupper terminal connected by a vconducting wire 7 with one terminal of arectifying detector 8 the other termi nal of said detector 8 beingconnected with one terminal of an electrical helix 10 by means of aconducting wire 9 the other terminal of said electrical helix 10 beingconnected by a conducting wire 11 with the lower terminal of saidsecondary winding 4 while an electrical condenser 12 is connected by oneof its terminals to the conducting. wire 11 and its other terminal tothe conductin wire 9-.

Similar y ondary winding 5 is connected by conductor 13 with oneterminal of another rectifying detector 14: whose other terminal isconnected by conductor 15 with one terminalofanother electrical helix 16whose other terminal is connected by a. conductor .17 with the lowerterminal of said secondary winding 5, there being another. electricalcondenser 18 which is connected with one of its terminals to conductor17 and its other terminal to conductor 15.

Within the helices 10 and 16 is movably disposed a magnetizable core 19whose central portion normally is surrounded by a longitudinally movablehelix 20 which may be referred to as the secondary helix of the core 19while the helix 10 and the helix 16 mav act as the primary coils of saidcore 19.

The direction of winding of the convolutions of wire of the helices 10and 16 respectively is such as to cause them to have the tendency tooppose each other in their inductive influence on the core 19 and thehelix 20 when both are subjected to the action of like electrical waves.

In practice I have foundit preferable to so construct and dispose insuitable supporting devices, not shown, each of the helices 10, 16, and20 and the core 19, that each independently may be moved horizontallywith relation to the others, whereby the helix 20, of larger internaldiameter, may be moved longitudinally in a direction toward either endof the core 19, to surround any desired portion of the helix 10 or thehelix 16 as required; or either or both of the helices 10 and 16 may bemoved longituthe upper terminal of said s'ecdinally to any position withrelation to the core 19 and the helix 20, and thus the core 19 and thehelices 10, 16 and 20 may be moved to positions with relation to eachother as desired to cause inductive influence of either one of thehelices 10 and '16 upon the helix 20 to be neutralized by the other ofsaid helices 10 and 16 whether such inductive influence be direct orthrough the magne'tizable core 19.

In 'Fig. 2 I have shown by view in longitudinalvertical section one formof the helices 20, 10, and 16 as. disposed on a core 19in a positionwherein it electrical waves of a given strength and of like character,be

caused to flow through helices 10 and 16 then no inductive influencecould affect the helix20, since the action of helix 1() would neutralizeor counteract the action of helix 16, but manifestly if the helix 20,the helix 10, the helix 16 or the core 19 alone be moved, then, in suchcase, the action on the different distant wireless stations, torepresent intelligible signals, find passageway through an',antenna, notshown, to the upper terminal of the primary winding 3 of an air-coretransformer and through said primary winding 3 to the earth 6, in amanner well known, .whereby corresponding waves are inductivelyimpressed in each of the two secondary windings 4 and 5, of saidair-core transformer, such waves generated in the secondary winding 4having a tendency to flow through wire 7 to and through the rectifyingdetector 8 thence through conductor 9 to and through the helix 10 andtherefrom through the conductor 11 back to thefsecondary winding 4; andsuch waves as are generated in said secondary winding 4 are alternatingin polarity, but to the extent of its capability the rectifying detector8 per I mits the passage through it of waves only of the same polarity,thus waves of such same 'rity, comprising what might be describe as anintermittent direct current, reachQQ and passes through the helix 10 byy the way of the conductor 9 while waves of different polarityvfind apassageway of little or no resistance through the 'condenser12; thus thehelix 10 is subjected only to waves of one like polarity. Likewise thewaves generated in secondary winding 5, passing through conductor 13 todetector 14: to be any waves traversing said helices 10 and 16 could notaflect the helix 20 to make perceptible signals in the receivingtelephone 21 but if one distant station be sending-out strong waveswhile another station is send ing out weak waves and if it be desired tohave the receiving telephone 21 affected only by the weak waves of suchother station then it would be necessary to adjust one of the twodetectors, say detector 8, to rectify strong waves only and then toadjust detector' 14 to rectify the weak waves with maximum 'efl'ect,whereupon the helix 20 should be moved away from the helix 10 toward thehelix 16 in the direction indicated by the arrow in Fig. 1, until thestrong waves in said helix 10 affect the helix 20 only to counteractaccurately the .effect of strong waves in the helix 16, whereby the coil20 will then be afi'ected only by the weakwaves of like polarity thathave been rectified by detector 14' which weak waves will perceptiblyaffect the receivingtelephone 21.

A movement of the core 19 toward the right or a movement of the helix 10toward the left for a; required distance may also cause or assist incausing the same result; and obviously the positions of the helices 10,16 and 20 may be changed to select the waves from any one of thestations irrespective of the. strength of such waves as compared tothefstrength of waves of other stations, provided, of course, all suchstations be within the range of the apparatus of my invention.

Manifestly, devices may be applied to the primary winding 3 or to the-secondary windings 4 and 5 for changing the number cuits includes oneof said secondary helices, two detectors one of which is connected inveach of said oscillating circuits in series with said secondary helixtherein, a condenser connected in each of said oscillating circuits inseries with said detector and said secondary helix therein, two primaryhelices each of which helices is connected with a different one of saidoscil lating circuits in parallel with the said condenser therein, amagnetizable core inductively and movably associated with both of saidprimary helices, a secondary helix movably and inductively associatedwith said magnetizable core and both of said primary helices and atranslating device connected with said secondary helix.

2. In a receiving apparatus of a wireless telegraph station, thecombination with a transformer having a primary helix that is adapted tobe connected with an antenna,

and having two secondary helices, of another transformer having twoprimary helices and one secondary helix, each of said primary helicesbeing disposed in electrical connection with a dilferent one of saidsecondary helices of said first named transformer, two detectors each ofwhich is dis posed in electrical connection with a different one of saidtwo secondar helices of said first named transformer, an areceivinginstrument disposed in electrical connection with the secondaryof saidsecond named transformer. a

In witness whereof, I, hereunto subscribe my name this27th day ofDecember A. D., v1912.

THOMAS BURTON MILLER.

I Witnesses:

FRANK WARREN, E. M. T001.

